Lubricator.



H. 0. WOODIBRIDGE.

LUBRIOATOR.

APPLICATION FILED MAB. 5, 1908. 904,107. Patented Nov. 17, 1908.

Wfm'esses:

Tax'dr 1n: Nun/us FII'IR: ca, wunmuruu, D. C.

HOWARD C. WOODBRIDGE, OF DUBOIS, PENNSYLVANIA.

LUBRICATOR.

Specification of Letters Patent.

Patented Nov. 17, 1908.

Application filed March 5, 1908. Serial No. 419,259.

To all whom it may concern:

Be it known that I, HOWARD C. 7001)- BRIDGE, a citizen of the United States, residing at Dubois, in the county of Clearfield and State of Pennsylvania, have invented a new and useful Improvement in Lubricators, of which the following is a specification.

This invention relates to an improved lubricator in which the oil reservoir or supply cup is provided with a piston or plunger which is reciprocated therein relative to the cup to feed the oil. to the part to be lubricated.

The object of the invention is to provide a lubricator of this character which will be positive and regular in its feed and in which there will be no waste of the lubricant and no parts to become clogged and stop the feed of the oil.

The device is especially adapted for lubricating the cylinders of air compressors although it may, of course, be used for various other purposes.

In the accompanying drawings: Fig ure 1 is a fragmentary sectional elevation of 1a lubricator embodying the invention, attached to the cylinder of an air compressor. Fig. 2 is a similar view showing the position of the parts when the air is compressed in the air cylinder and lubricator cup.

Like letters of reference refer to like parts in both figures.

A represents an oil reservoir or supply cup which is tightly closed at its upper end by a screw cap or other cover a and is provided at its lower end with a contracted neck a by which it is secured to the cylinder and which has a discharge opening or passage-way therein through which the oil is fed from the cup to the cylinder or other part to be lubricated. This cup is preferably cylindrical in form and is provided with a solid plunger or piston B which fits loosely within the cup and is free to reciprocate therein.

The passage way in the neck a of the cup communicates with the interior of the com pressor cylinder G, in which the piston c reciprocates, and the variations in pressure therein caused by the movements of this piston, are communicated through the neck passage-way to the interior of the oil cup below the plunger B. The oil cup above the plunger is partially filled with oil and the air inclosed in the space l) remaining in the cup above the oil forms an air cushion which permits the plunger and body of oil in the cup to be lifted by the increased pressure beneath the same during the compression stroke of the compressor piston. The air cushion is compressed by such upward movement of the plunger and oil and upon the intake stroke of the piston the expanding air cushion above the oil forces the same and the plunger down again. The plunger and body of oil are thus reciprocated in the oil cup during the operation of the compressor. The lubricator will operate in a similar manner if connected with any chamher in which the pressure fluctuates.

The fit of the piston in the oil cup is such that the piston can reciprocate freely while the oil will pack the space between the sides of the piston and the sides of the oil cup and prevent the compressed air from working past the piston into the upper portion of the cup.

The operation of the device is as follows: The normal position of the plunger B before starting the air compressor is in the lower portion of the oil cup, as shown in Fig. 1. \Vhen the compressor piston is moved and air is compressed in the cylinder, the pressure is communicated through the neck passage-way of the oil cup to the under side of the plunger B and lifts the plunger and the body of oil in the oil cup, as shown in Fig. 2, thereby compressing the air cushion in the upper part of the cup. As above explained, when the pressure is relieved on the intake stroke of. the piston, the plunger and the body of oil are forced do\\"nwardly by the expanding air cushion, the plunger and the body of oil being thus moved up and down or reciprocated within the oil cup. In the reciprocation of the plunger and body of oil 1n the cup, oil is left adhering to the walls of the cup and forms a thin film or layer of oil on the inner surface of the cup, and a portion of this oil gradually descends in the cup by gravity assisted by the downward movement of the plunger and oil body, which tends to drag and force the oil downwardly in the cup. Any shifting of the plunger sidewise on its downward stroke will cause it to scrape the oil from the surface of the cup with which it comes into contact and carry the same downwardly with it to the lower portion of the cup, whence the oil descends by gravity through the discharge opening to the part to be lubricated. The feed of the oil from the cup is determined to a considerable eX- tent by the length of movement of the plunger within the cup and this may be regulated by leaving a greater or less space or air chamber in the cup above the body of oil. The degree of compression and expansion of the air cushion and consequently the length of the strokes of the plunger and body of oil within the cup is also governed by the extent of the fluctuations or changes in the pressure on the under side of the plunger caused by the operation of the compressor piston, and inasmuch as the air cannot pass the plunger through the oil-packed space between the plunger and the walls of the cup, the size of the air cushion or space in the upper part of the oil cup will remain substantially constant, so that the length of the stroke of the plunger will remain substantially the same with each movementof the compressor piston irrespective of the decreasing amount of oil in the cup, thereby producing a practically constant feed of oil.

The reciprocating movement of the plunger within the cup is continued during the operation of the compressor, and this movement keeps the space between the sides of the plunger and the sides of the cup through which the oil passes, at all times free from obstruction by foreign matter in the oil, so that sediment or impurities in the oil will not interfere with the feed of the oil. As no valves are employed for regulating the feed of oil or controlling the pressure within the cup, and as a comparatively large discharge passage-way for the oil from the lower portion of the cup can be used, the danger of the stoppage of the feed resulting from the clogging of valves and discharge openings is still further lessened.

The area of the passageway for the oil formed by the space between the plunger and the sides of the oil cup is very much greater than the small orifices ordinarily employed in lubricators which feed a corresponding amount of oil and there is therefore much less danger of cloggingthis passage.

I claim as my invention:

1. A lubricator comprising an oil cup closed at its upper end, a plunger arranged to reciprocate within said cup with a body of oil in the cup above the plunger, an air space or chamber being left in said cup above said body of oil, and a discharge opening from said cup below said plunger, substantially as set forth.

2. A lubricator comprising an oil cup closed at its upper end and open at its lower end for the admission of fluctuating pressures and for the discharge of oil, and a plunger arranged in said cup to be reciprocated by such fluctuating pressures with a body of oil in the cup above the plunger, an air space or chamber being left in said cup above said body of oil, substantially as set forth.

3. A lubricator comprising an oil cup closed at its upper end and having a contracted opening at its lower end for the discharge of oil and for the admission of fluctuating pressures, and a plunger arranged within said cup to be reciprocated by such fluctuating pressures with a body of oil in the cup above the plunger, an air space or chamber being left in said cup above said.

body of oil, substantially as set forth.

itness my hand, this 26 day of February, 1908.

HOWVARD C. \VOODBRIDGE.

lVitnesses R. F. KLEINGUINO, C. H. BARRETT. 

